With a stalemate looming and the visiting fans' ire for Benitez and Torres increasing, Oscar came off the bench to score the winner eight minutes from time to give last season's Champions League winners the advantage ahead of next week's second leg of the last 32 tie at Stamford Bridge.
"Eighteen attempts away is not bad, but we have to be more clinical in attack," Benitez said.
"The first 20 minutes we were in control. After this 20 minutes they were pushing and pushing. The team, as a team, had problems defending.
"We changed a little bit in the second half. I think the concentration of the team was much better, the intensity in defence was much better and then we had more control."
Many of the missed opportunities fell to Torres, a £50million striker who now has one goal in 13 games.
"We have to create more opportunities and the strikers will score more goals," Benitez said.
"His work rate today was really good and thanks to him the rest of the team, especially the second line of offensive players, they could create.
"Everybody expects from a striker just to score goals, but he's doing also a great job for the team."
Meanwhile, Liverpool boss Brendan Rodgers insists his side are still in with a fighting chance of turning around their 2-0 last-32 deficit to Zenit St Petersburg.
Having missed a number of chances – with top scorer Luis Suarez being the main culprit – the Reds went behind to Hulk's brilliant long-range effort after 70 minutes with substitute Sergei Semak adding the second moments later.
It leaves Liverpool's hopes of progress in the balance in the return leg next week but Rodgers remains optimistic.
"There is no way the tie is over, not by a long shot. We are more than capable of getting the goals back," he said.
"The next goal is vitally important for us and what gives us hope is we created enough to win the game."